1. Field of the Invention
The present invention relates to the technical field of navigation system for movable bodies. To be more precise, the invention relates to the technical field of navigation system for movable bodies such as vehicles, which assists the users in locating places with a map displayed to them.
2. Description of the Related Art
In recent years, navigation systems for movable bodies such as vehicles, that assist the users to move from one place to another while displaying the map of destination, etc, are widely used. In conventional navigation systems, data corresponding to the information regarding the map, etc. to be displayed was generally read at a required timing only from optical disks such as DVDs where the data was previously stored.
In such conventional configurations, all the data required for navigation processing are read from the optical disks. Therefore, a series of processing such as searching the data in the optical disk, reading it, and displaying it, were required in each and every map.
Thus, the problem of inhibiting speediness occurs when, for instance, the needs arise to scroll the displayed map at high speed to search the destination.
In the mean time, research and development are actively carried out in recent years to have so called hard disk that enables high-speed data retrieval installed in the navigation system and the data required to display the map, etc. read from the hard disk.
However, when all the data required to display the maps were to be stored in the hard disk, everything including even the data for less frequently used maps were to be stored in it. In such case, a problem occurs so that the data for the maps that are frequently used and are really necessary to be stored in the hard disk may not be stored in it because the memory in the hard disk is limited, and the data for less frequently used maps occupy much space.
If a large capacity hard disk is installed in the navigation system in order to obtain more free space for storing the data for the maps that are frequently used, then another problem results so that it invites upsizing of the navigation system itself and the price increase.
It is therefore an object of the present invention to provide a navigation system for moving bodies, that can display required maps quickly and is downsized and lower priced making good use of the memory capacity to store the data for displaying maps.
The above object of the present invention can be achieved by a navigation apparatus for a movable body which assists in moving with a map while at least displaying the map. The navigation apparatus is provided with: a first information storing medium for storing map data corresponding to the map thereon; a detecting device for detecting displayed map data corresponding to the map already displayed at least once from the first information recording medium; and a recording device for recording the displayed map data detected by the detecting device on a second storing medium having higher access speed than the first information storing medium.
According to the navigation apparatus of the present invention, the displayed map data is stored on the second information storing medium. Accordingly, by detecting the displayed map data from the second information storing medium when the displayed map is displayed again, the displayed map data can be detected more promptly than that is detected from the first information storing medium, and the displayed map can be displayed.
Also, only the displayed map data is stored in the second information storing medium, so the free space in the second information storing medium will be utilized without losses. As a result, the second information storing medium is used efficiently, and downsizing and low price of the vehicle navigation apparatus as a whole including the second information storing medium can be realized.
In one aspect of the navigation apparatus, the displayed map includes at least the map including an area through which the movable body has ever gone.
According to this aspect, if the movable body goes through the area again, the displayed map including the area can be promptly displayed.
In another aspect of the navigation apparatus, the displayed map includes at least the map only displayed and not including an area through which the movable body has ever gone.
According to this aspect, the map displayed at least once can be promptly displayed again even if the map including an area through which the movable body has not gone actually.
The above object of the present invention can be achieved by a navigation apparatus for a movable body which assists in moving with a map while at least displaying the map. The navigation apparatus is provided with: a first information storing medium for storing map data corresponding to the map thereon; a detecting device for detecting displayed map data corresponding to the map already displayed at least once from the first information recording medium; a recording device for recording the displayed map data detected by the detecting device on a second storing medium having higher access speed than the first information storing medium; and a displaying device for detecting the displayed map data, corresponding to the displayed map to be displayed when the displayed map is displayed again, from the second storing medium and for displaying the displayed map again.
According to the navigation apparatus of the present invention, the displayed map data is stored on the second information storing medium, and the displayed map data is detected from the second information storing medium when the displayed map data is displayed again, then the displayed map corresponding to the displayed map detected is displayed. Accordingly, by detecting the displayed map data from the second information storing medium when the displayed map is displayed again, the displayed map data can be detected more promptly than that is detected from the first information storing medium, and the displayed map can be displayed.
Also, only the displayed map data is stored in the second information storing medium, so the free space in the second information storing medium will be utilized without losses. As a result, the second information storing medium is used efficiently, and downsizing and low price of the vehicle navigation apparatus as a whole including the second information storing medium can be realized.
In one aspect of the navigation apparatus, the displayed map includes at least the map including an area through which the movable body has ever gone.
According to this aspect, if the movable body goes through the area again, the displayed map including the area can be promptly displayed.
In another aspect of the navigation apparatus, the displayed map includes at least the map only displayed and not including an area through which the movable body has ever gone.
According to this aspect, the map displayed at least once can be promptly displayed again even if the map including an area through which the movable body has not gone actually.
In another aspect of the navigation apparatus, the navigation apparatus is further provided with a position detecting device for detecting a current position. Then, the displaying device extracts the map data corresponding to the map including the current position detected by the position detecting device from the displayed map data stored on the second storing medium when the map including the current position is included in the displayed map, and displays the map including the current position.
According to this aspect, if the map including the current position is included in the displayed map, the map including the current position can be promptly detected and displayed.
In another aspect of the navigation apparatus, the displayed map includes at least the map including an area through which the movable body has ever gone.
According to this aspect, if the movable body goes through the area again, the displayed map including the area can be promptly displayed.
In another aspect of the navigation apparatus, the displayed map includes at least the map only displayed and not including an area through which the movable body has ever gone.
According to this aspect, the map displayed at least once can be promptly displayed again even if the map including an area through which the movable body has not gone actually.
In another aspect of the navigation apparatus, the displaying device extracts the map data, corresponding to an adjacent map which is adjacent to the map currently displayed and is not currently displayed, from the displayed map data stored on the second storing medium when the adjacent map is included in the displayed map, and displays the adjacent map.
According to this aspect, if the map is displayed while being scrolled and the map to be scrolled is the displayed map, the map can be promptly detected and displayed and scrolled.
The above object of the present invention can be achieved by a navigation method for a movable body which assists in moving with a map while at least displaying the map. The navigation method is provided with: the process of storing map data corresponding to the map on a first information storing medium; the process of detecting displayed map data corresponding to the map already displayed at least once from the first information recording medium; and the process of recording the displayed map data detected by the process of detecting on a second storing medium having higher access speed than the first information storing medium.
According to the navigation method of the present invention, the displayed map data is stored on the second information storing medium. Accordingly, by detecting the displayed map data from the second information storing medium when the displayed map is displayed again, the displayed map data can be detected more promptly than that is detected from the first information storing medium, and the displayed map can be displayed.
Also, only the displayed map data is stored in the second information storing medium, so the free space in the second information storing medium will be utilized without losses. As a result, the second information storing medium is used efficiently, and downsizing and low price of the vehicle navigation system as a whole including the second information storing medium can be realized.
In one aspect of the navigation method, the displayed map includes at least the map including an area through which the movable body has ever gone.
According to this aspect, if the movable body goes through the area again, the displayed map including the area can be promptly displayed.
In another aspect of the navigation method, the displayed map includes at least the map only displayed and not including an area through which the movable body has ever gone.
According to this aspect, the map displayed at least once can be promptly displayed again even if the map including an area through which the movable body has not gone actually.
The above object of the present invention can be achieved by a navigation method for a movable body which assists in moving with a map while at least displaying the map. The navigation method is provided with: the process of storing map data corresponding to the map on a first information storing medium; the process of detecting displayed map data corresponding to the map already displayed at least once from the first information recording medium; the process of recording the displayed map data detected by the process of detecting on a second storing medium having higher access speed than the first information storing medium; and the process of detecting the displayed map data, corresponding to the displayed map to be displayed when the displayed map is displayed again, from the second storing medium and displaying the displayed map again.
According to the navigation method of the present invention, the displayed map data is stored on the second information storing medium, and the displayed map data is detected from the second information storing medium when the displayed map data is displayed again, then the displayed map corresponding to the displayed map detected is displayed. Accordingly, by detecting the displayed map data from the second information storing medium when the displayed map is displayed again, the displayed map data can be detected more promptly than that is detected from the first information storing medium, and the displayed map can be displayed.
Also, only the displayed map data is stored in the second information storing medium, so the free space in the second information storing medium will be utilized without losses. As a result, the second information storing medium is used efficiently, and downsizing and low price of the vehicle navigation apparatus as a whole including the second information storing medium can be realized.
In one aspect of the navigation method, the displayed map includes at least the map including an area through which the movable body has ever gone.
According to this aspect, if the movable body goes through the area again, the displayed map including the area can be promptly displayed.
In another aspect of the navigation method, the displayed map includes at least the map only displayed and not including an area through which the movable body has ever gone.
According to this aspect, the map displayed at least once can be promptly displayed again even if the map including an area through which the movable body has not gone actually.
In another aspect of the navigation method, the navigation method is further provided with: the process of detecting a current position; the process of extracting the map data corresponding to the map including the current position detected by the process of detecting a current position from the displayed map data stored on the second storing medium when the map including the current position is included in the displayed map; and the process of displaying the map including the current position.
According to this aspect, if the map including the current position is included in the displayed map, the map including the current position can be promptly detected and displayed.
In another aspect of the navigation method, the displayed map includes at least the map including an area through which the movable body has ever gone.
According to this aspect, if the movable body goes through the area again, the displayed map including the area can be promptly displayed.
In another aspect of the navigation method, the displayed map includes at least the map only displayed and not including an area through which the movable body has ever gone.
According to this aspect, the map displayed at least once can be promptly displayed again even if the map including an area through which the movable body has not gone actually.
In another aspect of the navigation method, the navigation method is further provided with: the process of extracting the map data, corresponding to an adjacent map which is adjacent to the map currently displayed and is not currently displayed, from the displayed map data stored on the second storing medium when the adjacent map is included in the displayed map; and the process of displaying the adjacent map.
According to this aspect, if the map is displayed while being scrolled and the map to be scrolled is the displayed map, the map can be promptly detected and displayed and scrolled.